Hand held string trimmers are used in lawn and yard maintenance by homeowners and professionals. These trimmers include an electric motor or gasoline engine that rotates a hub from which a string projects. The rotation of the hub creates centrifical force which holds the string away from the hub. The operator manually guides the string trimmer so that the rapidly moving string comes in contact with vegetable matter such as grasses and weeds and severs the grasses and weeds at the point of contact.
The string used by the trimmer is commonly a nylon or other non-metallic monofilament and i s worn away by contact with vegetable matter or extra hard material such as woody plants or concrete. Many string trimmers include a supply of string to replenish the worn away portion of the string projecting from the cutting head. Such string trimmers commonly contain a semiautomatic or manual mechanism for advancing additional string from the supply to replace that string worn away outside the cutting head. When the original supply of string that is sold with a new string trimmer is exhausted the string must be replenished. The supply of string is commonly wound upon a removable and replaceable hard plastic spool or attached to a fixed line trimmer head. The quickest way to replenish the supply of string is to purchase a replacement spool which has the string prewound thereon. Prewound spools are available to homeowners and professionals. Although this method is simple it has the disadvantage of high cost. For continued use of the string trimmer there are other methods available for the trmmer operator to reload an empty spool. The operator may reload the empty spool by hand winding the string in accordance with instructions supplied with the purchase of the trimmer, or use a spool winding apparatus available for purchase in commerce. Another method for continued use of the string trimmer is to replace the semiautomatic manual mechanism for advancing additional line with a fixed line head. Fixed line heads are available for purchase by homeowners and professionals.
Trimmers that use fixed line heads do not have a supply of string that can be advanced when the string is worn away. The fixed line head has an attachment means whereby short lengths of stringline can be attached; commonly one or two pieces of stringline are attached in a fixed position so that two or four ends extend substantially equal distance outside the hub. The cutting action is the same as other hand held trimmers described above. The only difference is that when string is worn away the remaining portion must be removed and replaced with new stringline.
There is little commonality in the size of trimmer spools used by differing manufacturers. The same is true of the manner in which the stringline is attached to spools. Some use single lines and some use dual lines and the method of attaching the stringline varies considerably. Many manufacturers use a single hole slightly larger than the diameter of the stringline; others use a plurality of holes to accommodate both single line and dual line spools. Then again there may be a single hole adjacent to the spool hub and its side wall wherein the dual stringline is looped through to a center point for rewinding onto the empty spool. All methods have problems in withdrawing, cutting, measuring and attaching stringline to rewinding an empty trimmer spool or attaching stringline to a fixed line trimmer head.
Monofilament stringline is available for purchase in various size packages or spools, the length of which range from approximately 50 feet to thousands of feet. The manner of packaging, spool or coiled packages, presents many problems for the user. Upon removal the line is in a semi-coiled state, more so with smaller packaging, and can quickly become tangled beyond useability.
The trimmer operator may use replacement string from a bulk supply or purchase a prewound spool or purchase precut short lengths of stringline for use in a fixed line head. Due to the high cost of prewound spools and precut stringline, high volume users of string trimmers choose to cut stringline from a bulk source such as one pound donut packages or larger bulk source such as three and five pound spools. There is little commonality for removal of stringline from a bulk source. Some operators improvise to obtain the required stringline from a bulk source, which often results in tangled unmanageable kinked line. There are dispensers available for purchase; however, due to high cost or lack of suitability, few are being used by homeowners and lawn maintenance companies. When stringline is removed from a bulk source two hands are required to measure and cut the recommended lengths.
Hand held tools are generally used to cut stringline, such as side cutting pliers or similar cutting tools, which have several disadvantages. Hand held tools are awkward to use and must be laid down and picked up several times during the measuring and cutting process. Also, hand held tools are easily lost or misplaced and do not always cut the stringline efficiently. The line is mashed out of shape at the point of cut or is not cut, which requires reshaping or repositioning the line for a recut which creates an attachment problem in that the holes provided are generally slightly larger than the diameter of the stringline. Therefore a mashed line is impossible to place in holes provided.
Thus there is a need for a device to which a bulk stringline source may be rotatably mounted and from which stringline may be rotatably transferred direct to an empty trimmer spool or be quickly withdrawn and cut without being tangled or mashed for hand winding onto an empty trimmer spool.
Furthermore there is a need for a cutting device that eliminates the awkward hand held cutting tool which can be permanently mounted, and that cuts all sizes of stringline, such as 0.065, 0.080, 0.095, 0.105 and 0.130 every time without being mashed, for use in rewinding empty trimmer spools or for use in fixed line trimmer heads. Various cutting devices have been developed that use grooves and slots for cutting guides to miter cuts in such material as wood, rubber, plastic and string yarn. For example:
Griffith U.S. Pat. No. 592,139 discloses miter boxes to guide a saw in cutting kerfs for the formation of dovetail connections between sides and ends of boxes and other rectangular receptacles formed of wooden boards or other available materials.
Ludwig U.S. Pat. No. 1,718,791 discloses miter bixes for cutting mitered ends in corner beads, coping or other metal strips folded, shaped or formed from sheet metal; further the invention provides a channel shaped miter box for corner beads which provides adjustable supports mounted within the channel body portion which may be moved vertically to accommodate different shapes or sizes of corner beads.
Curacio U.S. Pat. No. 3,782,235 discloses an improved miter box for use by carpenters and others in making miter joints particularly for mitering picture, cove, casing and base moldings. The general improvement lines in substituting a square shaped box for the conventional U-shaped form, and making this miter box in the form of a single integrally molded transparent plastic unit. It improves durability of the miter box and increases precision in cutting because the saw will not easily cut into the saw cutting guide of its side walls.
Wylier U.S. Pat. No. 3,811,356 discloses a miter box having spaced saw kerfs arranged in aligned pairs and having a horizontal bottom formed by two mating horizontally elongated horizontal members detachably engageable in abutting coplanar relationship wherein means are provided for detachable insertion between said horizontal members to enlarge the width of the box.
Slemmons U.S. Pat. No. 3,837,253 discloses an E-shaped cross section guide for cutting art frames and similar materials. This guide comprises three parallel ridges coupled to base and spaced so that two parallel planar portions of the poster frame slide and fit snugly over the center ridge for cutting 90.degree. angles and 45.degree. angles to be used for mitering poster frames.
Ludvik U.S. Pat. No. 4,093,200 discloses a device for cutting yarn which comprises a drum having a plurality of narrow grooves in the outer surface for holding the yarn in place on the outer surface of the drum and base support for holding the drum.
Rouse U.S. Pat. No. 4,095,500 discloses an accurate, inexpensixe angle cutting guide for use in carpentry which gives a saw a rigid and perfect guide for any 45.degree. or 90.degree. cut whether the cut be horizontal or perpendicular. This invention is a miter box employing slots of various angles such as 45.degree., 90.degree., and 135.degree. to make miter joints particularly for mitering picture, cove, casing and base moldings.
Horwath U.S. Pat. No. 4,281,827 discloses an improved miter box that allows crown molding to be cut in the same orientation in which it will be installed to assure a perfect miter joint. Further a miter box is disclosed for holding a longitudinal work piece to be cut by saw or other cutting device at a measured angle parallel to the longitudinal axis of the work piece and simultaneously at a second angle measured in a plane perpendicular to the longitudinal axis of the work piece.
O'Neill U.S. Pat. No. 4,436,014 discloses a miter box suitable for cutting a mitered end on a strip of L shape in cross section that has a receiving slot extending from edge to edge in an upper surface to receive the strip of material and two cutter guide slots at right angles to one another, the slots having a common intersection with the receiving slot at one of the edges of the upper surface.
Stoller U.S. Pat. No. 5,522,296 discloses a cove base cutting guide comprising slits at various angles, typically 90.degree. +45.degree. and -45.degree. to the chamber, such that a cove base in the chamber is cut at a given angle by a utility knife in the slit.
Nicholson U.S. Pat. No. 5,056,732 discloses a device for winding line onto a trimmer spool that is generally cut with hand held tools and relates more particularly to an apparatus for winding plastic line such as nylon monofilament string onto a non-metallic spool for use in a hand held string trimmer.
Wallace et al U.S. Pat. No. 4,073,059 discloses a hand held pruning shear of the hook style or pass-by type wherein the crossed layers are pivoted in combination with a power element providing a severing function which is specifically designed for cutting woody plants and would be inefficient for cutting tough semirigid plastic stringline.
Prior art references cited to Stoller U.S. Pat. No. 5,522,296 are listed by name and U.S. Patent Number only as each is listed separately above:
Griffith U.S. Pat. No. 592,139 PA1 Ludwig U.S. Pat. No. 1,718,791 PA1 Curcio U.S. Pat. No. 3,782,235 PA1 Wyler U.S. Pat. No. 3,811,356 PA1 Slemmons U.S. Pat. No. 3,837,253 PA1 Rouse U.S. Pat. No. 4,095,500 PA1 O'Neill U.S. Pat. No. 4,436,014 PA1 Wallace et al U.S. Pat. No. 4,073,059